Compressor apparatus



March 5, 1963 ca. H. SUDMEIER 3,080,495

COMPRESSOR APPARATUS Filed May 13, 1958 2 Sheets-Sheet 1 INVENTOR. 6'03 m vfi. Jami/2 March 5, 1963 G. H. SUDMEIER COMPRESSOR APPARATUS Filed May 13, 1958 24 ,zzz

6 g 5 WW Z I W W L w a m m C C livApapn-rae I; .22 jawnasmfl I N V EN TOR. v19; 300/75/52 United States Patent Gfitice 3,08tl,495 I .COMPRESSGR APPARATUS H.'Sudmeier, 2708 Torrance, Torrance, lCalif. Filed May 13,1958, SenNo. 735,008

2 Claims. ((1 310-104) Gustav ,This invention relates generally to fluid compressor apparatus, and more particularly to, a fluid compressor apparatus adaptable for use in refrigeration systems.

. An ever-present problem in refrigeration systems of the type employinga compressor and circulating refrigerant, lies in the loss of refrigerantfrom the system and particularly from the compressor. It has previously been proposed to avoid the loss of refrigerant in systems of this type by enclosing the compressor in a hermetically-sealed chamber. Of course, due to the fact that the compressor is normally driven by an electrical motor, to avoid the existence of a drive shaft passing through the sealed chamber, it has been customary to enclose the motor as well as the compressor. Although arrangements of this type render the motor inaccessible for maintenance, requiring degasification of the system to gain access to the motor, such systems provide a considerably-improved arrangement wherein alternating-current motors are employed. However, in the event that direct-current motors are used this arrangement does not provide a solution. Electrical arcing is invariably present in motor, for example at the commutator, and if a directcurrent motor is enclosed in an atmosphere of refrigerant, the arcing is likely to effect a chemical change in the refrigerant to form various acids which are corrosive to the refrigeration system. Therefore, compressors which employ direct-current electrical motors have not generally been housed in hermetically sealed chambers, and as a result losses of refrigerant have been tolerated.

When compressors, or other apparatus employing mov-' ing parts, are hermetically sealed, the inaccessibility of the apparatus demands that the maintenance requirements of the apparatus be reduced as much as possible. Of course, the moving parts of the apparatus must be lubricated in order to functionproperly; therefore, it has previously been proposed to employ the compressed fluid, e.g. circulating fluid refrigerant, in a compressor to carrylubricant in; suspension to the friction surfaces in the compressor. However, if the refrigerant is the elficiency of the refrigeration system is considerably reduced. Therefore, there is a need for a method and apparatus for providing lubricant to the moving parts of an apparatus in a sealed chamber by means of a circulating fluid, in which the efiiciency of the system employing the apparatusis not substantially reduced.

Many different types of small compressors for refrigera tion use have been proposed in the past; however, there remains a need for a small, efficient compressor that is economical to manufacture and which possesses light weight and is flexible in its application so as to be capable of being mounted in various positions.

The present invention, prises a refrigeration system utilizing a small compressor which is hermetically-sealed separately from the driving motor. In the apparatus, the driving motor is coupled to the compressor through a sealed non-ferrous plate, by employing magnetic coupling. The

a synchronous drive between the motor and the com-- therefore if for any pre'ss'or, i.e. coupling without slip, reason the compressor falls out of synchronism with the motor, the coupling is broken. The present invention a direct-current Well saturated with lubricant,

in its more general form comcoupling includes magnetic'toroids positioned upon each side of the non-;

thereforeincludes a control system which functions to sense the occurrence of a break in the magnetic coupling, to de-energize the motor for a brief interval whereby the motor may come to a stop and allow the magnetic coupling to become re-established. I

Furthermore, the present invention provides an improved compressor structure, which is lubricated by a lubricant carried by the refrigerant. Means are incorporated in the system for controlling the refrigerantis saturated with lubricant, thereby maintaining the efli'cie'ncy of the refrigeration system relatively high.

It is therefore a major object of the present invention to provide an improved refrigeration system. 1

It is another object of the present an improved fluid compressor.

till another object of the a" compressor unit employing a direct-current motor, wherein the compressor unit is hermetically sealed.

A further object of the present invention is to provide an improved coupling apparatus whereby motion may be transmitted through a closed chamber.

Still a further object of the vide an improved system for lubricating the friction surfaces in an enclosed compressor.

A still further object ofthe present invention is to provide an improved control system for use in conjunction with a magnetic coupling,

These and other objects and advantages of the present invention will become apparent from the following specification and accompanying drawings in which:

FIGURE 1 is a perspective view of a compressor unit incorporating the principles of the present invention;

FIGURE '2 is an enlarged vertical sectional view taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a partial vertical sectional view taken along the line 3-3 of FIGURE 2;

FIGURE 4 is a vertical sectional view taken along the line 4-4 of FIGURE 2; a 7

FIGURE 5 is a vertical sectional view taken along the line 5-5 of FIGURE 2; V

FIGURE 6 is a partial horizontal sectional view taken along the line 6-6 of FIGURE 2; and

FIGURE 7 is a-diagrammatic representation of a re frigera-tion system and electrical control system incorporating the principles of the present invention.

Referring now to the drawings and particularly to FIGURE 1 thereof, there is shown a direct curren-t motor ltl having a housing-l2 mounted thereon. The housing 12 contains a control circuit (hereinafter described) and provides a pair of terminals to which are adapted to be connected to a source of direct-current power to energize the motor 10. The motor 16 is rigidly aflixed and coupled to a compressor l6, which will be more fully de-' In the operation of the compressor fluid, e.g. gaseous the compressor 16 through refrigerant, is drawn into a tube 24 at a relatively lowpressure and exhausted from the compressor through a tube 26 at a relatively high pressure. Of course, the gaseous fluid from the extent to which the" invention to provide present invention is to'proof the motor 10,

assua e tube 25 may be employed in refrigeration apparatus as hereinafter described.

Reference will now be made to FIGURE 2 for a consideration of the manner in which the motor in is coupled to drive the compressor 16. The motor 10 has a divided housing formed of a major housing 28, constructed in accordance with conventional motor techniques, and an end housing cap 3%) which carries a bearing 32 that in turn supports the drive shaft 34 of the motor. A pair of bolts 35 serve to hold the cap 3f) to the housing 28. Thus the operating components of the motor are readily acwssible simply by removing the bolts 35.

A backing plate 36 is affixed to the drive shaft 34 of the motor m by a set screw 38. The plate 36 is formed of ferrous material and is circular in form. A toroid 4d, formed of ferrite material, is rigidly affixed upon the backing plate 36. Of course, other ferrous materials, having considerable magnetic retentiv-ity may also be used in forming the toro-id 4%. In the event that the toroid so is formed of a ferrite material, it may be affixed to the plate so by a synthetic resin adhesive.

The motor in is held in rigid engagement with the compressor 16 by a plurality of'studs 42 which pass through an external rim of the cap 3% and a circular non-ferrous plate 44 to threadably engage an end section as of the compressor housing. The non-ferrous plate d4 may for example, be formed of fiber glass impregnated with synthetic resin. The separator or plate 44 has a center section 48 of increased thickness (FTGURE 4) which is concentric to the plate. The motor it? is affixed to the compressor 16 so that the toroid 4th is positioned contiguous to the plate 44, and the center section 48 lies within the toroid 4d. The center section 48 of the plate 44 reinforces the plate against flexing under pressure and rubbing against the revolving members as the toroid 40.

At the compressor side of the plate 44 a toroid b is positioned, which also receives the center section 43 of the plate 44. The toroid 5G is similar to the toroid ll and is affixed upon a backing plate 52 which is in turn mounted upon a shaft 54 of the compressor and there held by a set screw 56.

A counterbalance 58, in the form of a circular segment, is adhered to the compressor side of the plate 52 to offset the weight of the reciprocating portion of the compressorj This member may consist ofresin impregnatedfiberglass, and be adhered to the plate 52 by resin.

The toroids 4ft and 5t) contain a magnetic pattern as shown in FIGURE 3, which includes a number of alternate north and south pole radially-extending mag netized areas 60. In providing the magnetic pattern as shown in FIGURE 3, considerable potential energy is contained by the state of the toroids. Therefore these members are formed as toroids to avoid a center section wherein a large number of magnetic interfaces would be closely positioned which would tend to be diflicult to maintain. That is because the magnetized members are toroidal in shape, the proximity of the radial magnetic interfaces may be spaced apart and thereforethe remanence of magnetic pattern is higher or more lasting.

Referring now to FIGURE 2, it may be seen that the magnetic coupling between the toroids 40 and 50 positioned in faced-opposing relationship includes a number of magnetic circuits, e.g. eight circuits which pass through the backing plates 36 and 52, the toroids 4t) and 5d, and the non-magnetic gap including the plate 44. In the operation of the coupling, the toroids 4t) and 56 are locked together by the magnetic lines of force in these magnetic circuits, therefore the energy of motion which appears at the shaft 48 is transferred through the ma netic coupling to the shaft 54.

Referring now to FlGURES 2 and 5, a consideration will be made of the components of the compressor apparatus. The compressor shaft 54 is formed integral with a crank shaft 64 that terminates in a shaft 66 which is journaled into a bearing 6%. The crank shaft 64 carries a connecting rod 7ft by means of a rod bearing 72. The connecting rod '70 is in turn connected to a Wrist pin 74 mounted in a piston 76. A small wick 77 (FIGURE 2) is positioned between the piston 76 and the top of the connecting rod 70. The wick '77 receives lubricant from the circulating fluid which carries suspended lubricant. The wick provides lubricant for the wrist pin 74.

The piston 76 is positioned within a cylinder '78 supported upon the end section 46 of the compressor housing by studs 89. By loosening the studs 8%, the cylinder may be adjusted vertically over a small distance to compensate for variations in the compressor components. The cylinder 73 is formed to include extensions 82 (FIG- URE 5) which contain bores that receive the ends of a lubricating wick 84.

A valve plate 85 (FlGURE 2) is positioned over the top of the cylinder 78 and contains intake and exhaust ports. Contacting the lower, or internal surface, of the valve plate 36 is a reed 918 (FIGURE 6) which includes extensions @d and 92 that cover ports in the valve plate 86 which are mated with similar ports in a cylinder head 94. lit is to be noted, that the ports are opened as the reed $3 is flexed over a curved fulcrum surface 94' of the cylinder 73. As a result, the flexing reed 88 does not encounter a sharp surface and is capable of extended perind-s of operation. a V

The cylinder head 94 is'affixed to the cylinder 78 by studs 95 (FIGURE 5) and contain a passage (FIGURE 2) which is connected to the exhaust tube 26. An exhaust valve plate 96 is held within the cylinder head on pins 93 which also carry springs res that urge the plate downwardly to cover a port 1% in the valve plate 86.

' Of course, when the pressure within the cylinder 78 exseeds the pressure in the cylinder head 74 by a predetermined amount, the springs llflfi yield thereby opening the port M92 and enabling fluid to pass from the cylinder into the exhaust tube 2%.

' in the operation of the compressor as considered above, the motor iii revolves the shaft 34 which is coupled to the shaft as through the plate 4 2 by the toroids 4d and 5t) and by magnetic flux. Revolution of the compressor shaft '54- reciprocates the piston 76 by means of the connecting rod 7i to perform the compressing operation.

In considering the intake or down stroke of the piston 7d, it is to be noted that the low pressure intake 24 is connected to the interior of the compressor housing through a tube lit i (FIGURE 5), therefore, the initial flow is into the housing. Inside the compressor housing, the tube 1% divides into a short open section 1% and an extended restricted section 1%. In passing through the tube the, the circulation fluid is impinged against the surface of the inner wall of the tube and oil or other lubricents which may be carried in suspension by the gaseous fluid is deposited upon the surface. The gaseous fluid then passes throughthe upper section 1% of the tube Mi -l to discharge into the compressor housing. The lubricant deposited upon the tube surface drains out of the tube section 108. Of course, some gaseous fluid also passes through the section M38 forcing lubricant from a nozzlelike section ill of the tube 104, to be sprayed upon an exposed portion of therod bearing 72. Of course, the rod bearing is channeled to receive the lubricant. It is to be noted, that by reason of this arrangement the amount of lubricant carried by the refrigerant is somewhat controlled as lubricant is continually removed by impingement of the gaseous fluid against a surface in the tube 104. Furthermore, it is to be noted that free lubricant in the compressor is taken up by the wick 84 which provides lubricant to the piston '76. Of course, by avoiding the use of unconfined lubricant which would normally be splashed about within the compressor and by removing lubricant from the refrigerant, the'amouut of lubricant carried by l the" refrigerant is somewhat controlled" and maintainedrelatively' low thereby maintaining the efiicie'ncy of the system at a higherlevel.

v 'I'he'fluid refrigerant contained inthejcompressor housing at a rela'tively'low" pressure is drawn thr'cugh'po-rts in'the' cylinder head'94 and the valve plate 86 during a downst'rokeflof' the piston '76. Thejfiuid is permitted to pass through thecylinder head 94 an'dfthe valve plate During an upstroke of the piston 76, the fluid, e.g. gas-' eons refrigerant, is compressed to exert a pressure upon the'exhau'stvalve plate 96 (FIGURE 2) which moves up-' the'spring 1tltl,"to allow the fluid wardly; by compressing to pass through a port 102 into the exhaust tube'26;

In view ofthe above description,"it maybe seen that the fluidc'ompressed by thecompressor'ldis maintained within the compressor by a positively sealed structure. Thus, the compressor of the present invention is hermetically sealed yet does not enclose the drive motor and can therefore employa direct current motor. It is also to be noted that none of the compressors output serves to maintain seals 'orothe'r closure mechanisms in the compressor.

It is also "to be noted, that the compressor incorporates a novel lubricating system which employs the fluid of the compressor to carry lubricant; however the lubricant content of the fl'uid is somewhat controlled and does not reach saturationand decrease the efi'iciency of operation in 'a"refrigeration system.

As previously indicated, the magnetic coupling between the toroidsdtl and 59 is locked therefore,jthe compressor 1-6 i'sdriven in synchronism with the motor 10. In the event ota break in the magnetic coupling between the compressor and the motor it is necessary to stop the motor to enable themagnetic coupling to become re-established. Also, the magnetic coupling may not possess suflicie'nt strength to allow the compressor to be started under load conditions. Of course, unless the compressor is given'a period to balance the various pressures therein aftershut-dowvn, the torque re uired for starting'the comfpressor may be considerable.

Upon the occurrence of a break in the magnetic coupling, the motorltl would c'on'tinu'e'to revolve Qunde'r no load "conditions 'withthecoinp'ressor 16idle. To preventthe oeeurrenceof operation failures of this type, on automatic electrical control system is provided for use in coniunction with the mot-or 1G and the compressor 16, which functions to sense the occurrence of a failure in the magnetic coupling and to de-energize the motor upon such an occurrence, and allow the motor to halt and re-establish magnetic coupling. A delay interval may also be provided by the control system during which the motor remains stopped while the various pressures within the compressor 16 balance out to allow the motor to start under no-load conditions.

Referring now to FIGURE 7, the control system of the present invention will be considered. A compressor 112, which may comprise the compressor described above, is connected to a condenser 120. The condenser is in :turn connected to an evaporator 118 which is connected to the compressor block 112 to form a conventional refrigeration system. A thermostat 124, associated with the evaporator 112 functions to control a switch 126 in accordance with the temperature of the evaporator 118. The capillary 116, along with the evaporator 118 and the condenser 120 may be standard refrigeration system components and, as previously indicated, the compressor 112 may comprise a compressor as previously described herein. The compressor 112 is mechanically coupled to a motor 128 which may be the motor 10 and which opports through the valve plate and the erates' the'compressor accordance with the temperature" of theevaporator'118, .undercontrol of the switch 126 and a control circuit 139.

Injthe'jcontrolcircuit'13tl, a pair of lines 132 and 134 are adapted to be connected to a source of direct current power as through terminals 14 (FIGURE 1). The

rent-receiving line 132 is connected to the movable co'ntact of contacts 156 and to the movable contact ofcon tacts 152. The movable contact of contacts 152 also engages a second stationary contact to form contacts 154. i

In the operation of t esystem, the resistance element 146 functions to heat a bimetallic blade of the type wellknown in theart, whichmay comprise the movable contact'of the contacts 1%. Heating of the blade opens the contacts 156. Additionally, the bimetallic blade is mechanically coupled to the contacts 152 and prevents the closureof contacts 152 until such time as the bimetallic blade is heated to a predetermined temperature.

An understanding of the controlcircuit may now best be effected by considering a cycle of operation thereof. Assume'that the lines 132 and 134 are connected to a source of direct current and that the temperature of the evaporator 118 has reached a level so that the thermo-' stat124 functions to close the switch 12s. Electrical the line 134, the switch 126,

current then flows through the'motor 128', and hold coil 138, the activate coil 140, the contacts Inset-and 152 then through the line 15-8 back t-o the' line 132. During the initial surgeof this current, the contacts of the relay 137 are and opening thecontacts 152 and 148. Upon thecompletion of this switching-operation, it is to be noted that the'a'ctiv'ate coil 14%} is shorted out through the contacts 142 and1'54, line 158, and contacts 150.

The motor 128 now continues, to run with the control circuit 13c consumingessentially no energy, the only en-' ergy being that required to maintain the relay 137 in anenergized position by the energization of the hold coil 133.

motor 123 begins to run this occurrence the current through the motor 128 Will decrease substantially as Will the current in the serially thermal heating eletemperature.

contacts in the above-described state, the thermal element 146 is energized by current passing from the line 134, through the line 144, the element 146, contacts 143, contacts 154 and the line 158. After a predetermined interval, during which the motor 123 stops and the pressures in the compressor 112 balance out, the heating element 146 heats the bimetallic element to an ade quate temperature to open the contacts 156, and allow the contacts 152 to close. Upon this occurrence the current passing through the contacts 152 is interrupted and the resistance element 146 is de-energized. However, the contacts 156 remain open for a brief interval until such time as the bimetallic blade associated with the element 146 cools sufiiciently to enable the contacts 146 to close. Upon closure or" the contacts 156 the motor 128 is again energized in the manner first described.

The other direct cur-' raised by the activate; coil lhthereby closing the contacts 150, 154, and 142,

operation of the motor s,oso,4.es

Of course, it is to be understood that the time delay may be varied to allow various periods for the magnetic coupling to become re-estahlished. Such variations may be effected in accordance with well-known practices either by varying the resistance metallic blade associated therewith.

It may therefore be seen, that in the event that the motor 128 becomes decoupled from the compressor 112 for any reason, or if coupling is never effected due to the system attempting to operate prior to the balancing of pressures in the compressor, the control system 133: senses such an occurrence and temporarily delays the 123, enabling the system to prepare for a subsequent start-up operation.

An important feature of the control system of the present invention resides in the mode of operation which does not require substantial energy demands during nonoperating intervals.

It should be noted that although the particular ernbodiment of the invention herein shown and described is fully capable of providing the advantages and achieving the objects previously set forth, such embodiment is merely illustrative of this invention and therefore modifications and changes may be made thereto'without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. A drive system for inter-coupling first and second concentric aligned mechanical shafts, comprising: a first homogeneous toroid of magnetic material having a flat annular surface containing an even plurality of alternatepolarity elongate magnetic pole faces extending radially fully across said annular surface; first mounting means for affixing said first toroid to said first shaft whereas said first toroid is concentric with said first shaft and said annular surface of said first toroid is face-opposing said second shaft; a second homogeneous toroid of magnetic material having a flat annular surface containing a like even plurality of alternate-polarity elongate magnetic pole faces extending radially fully across said annular surface; second mounting means toroid to said second shaft whereas said second toroid is concentric with said second shaft and said annular surface of said second toroid is face-opposing said first shaft; and a housing substantially enclosing one of said toroids, and including a flat separator of non-ferrous material supported and contacted solely by said housing and positioned between said fiat annular surfaces of said first and second toroids whereby said toroids are magnetically interconnected and physically separated.

heating element M6 or the bi- 2. A drive system for inter-coupling first and second concentric aligned mechanical shafts, comprising: a first homogeneous toroid of magnetic material having a flat annular surface containing an even plurality of uniformlyspaced alternate-polarity elongate magnetic pole faces extending radially fully across said annular surface and having a length greater than the internal diameter of said first toroid; first mountingmeans for affixing said first toroid to said first shaft 'whereas said first toroid is concentric with said first shaft and said annular surface of said first toroid is face-opposing said second shaft; a second homogeneous toroid of magnetic material having a fiat annular surface containing a like even plurality of uniformly-spaced alternate-polarity elongate magnetic pole faces extending radially fully across said annular surface and having a length greater than the internal diameter of said second toroid; second mounting means for affixing said second toroid to said second shaft whereas said second toroid is concentric with said second. shaft and said annular surface of said secondtoroid is faceopposing said first shaft; and a housing substantially enclosing one of said toroids, and including a fiat homogeneous separator of non-ferrous material supported and contacted solely by said housing and positioned between said fiat annular surfaces of said first and second toroids wherea by said toroids are physically separated and magnetically for afilxing said second coupled, said separator having an integrally-formed center section of increased thickness extending axially into each of said toroids whereby to provide additional support for said toroids.

References fitted in the file of this patent UNITED STATES PATENTS 593,571 Fay Nov. 16, 1897 2,074,738 Aikman Mar. 23, 1937 2,317,135 Crittenden Apr. 20, 1943 2,366,562 Schug Jan. 2, 1945 2,386,505 Puchy Oct. 9, 1945 2,573,126 Andrus Oct, 30, 1951 2,638,558 Rankin May 12, 1953 2,669,668 Oltulitch Feb. 16, 1954 2,705,762 Pile Apr. 5, 1955 2,885,126 Hudson May 5, 1959 2,885,873 Beeston May 12, 1959 FOREIGN PATENTS 513,224 Belgium Aug. 14, 1952 529,405 Canada Aug. 21, 1956 554,215 Germany July 6, 1932 

1. A DRIVE SYSTEM FOR INTER-COUPLING FIRST AND SECOND CONCENTRIC ALIGNED MECHANICAL SHAFTS, COMPRISING: A FIRST HOMOGENEOUS TOROID OF MAGNETIC MATERIAL HAVING A FLAT ANNULAR SURFACE CONTAINING AN EVEN PLURALITY OF ALTERNATEPOLARITY ELONGATE MAGNETIC POLE FACES EXTENDING RADIALLY FULLY ACROSS SAID ANNULAR SURFACE; FIRST MOUNTING MEANS FOR AFFIXING SAID FIRST TOROID TO SAID FIRST SHAFT WHEREAS SAID FIRST TOROID IS CONCENTRIC WITH SAID FIRST SHAFT AND SAID ANNULAR SURFACE OF SAID FIRST TOROID IS FACE-OPPOSING SAID SECOND SHAFT; A SECOND HOMOGENEOUS TOROID OF MAGNETIC MATERIAL HAVING A FLAT ANNULAR SURFACE CONTAINING A LIKE EVEN PLURALITY OF ALTERNATE-POLARITY ELONGATE MAGNETIC POLE FACES EXTENDING RADIALLY FULLY ACROSS SAID ANNULAR SURFACE; SECOND MOUNTING MEANS FOR AFFIXING SAID SECOND TOROID TO SAID SECOND SHAFT WHEREAS SAID SECOND TOROID IS CONCENTRIC WITH SAID SECOND SHAFT AND SAID ANNULAR SURFACE OF SAID SECOND TOROID IS FACE-OPPOSING SAID FIRST SHAFT; AND A HOUSING SUBSTANTIALLY ENCLOSING ONE OF SAID TOROIDS, AND INCLUDING A FLAT SEPARATOR OF NON-FERROUS MATERIAL SUPPORTED AND CONTACTED SOLELY BY SAID HOUSING AND POSITIONED BETWEEN SAID FLAT ANNULAR SURFACES OF SAID FIRST AND SECOND TOROIDS WHEREBY SAID TOROIDS ARE MAGNETICALLY INTERCONNECTED AND PHYSICALLY SEPARATED. 